Refrigerator, air cooler, and the like



Dec. 29, 1942. I 1.7M. KETCHAM 2,306,480

REFRIGERATOR, AIRCOOLER, AND THE LIKE Filed Dec. 29, 1934 2 Sheets-Sheet 1 Ill 1 e l| .g; I 55 r I l 7 q; :1: Q

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' mvizmoa- [)W/A/ /ZAEft/MM ATTORNEY Dec. 29, 1942 l. M. KETCHAM REFRIGERATOR, AIR COOIIER, AND THE LIKE 2 She qfcs-Sheet 2 Filed Dec. 29, 1934 I I o z I myEN'rdR [Rum M Kira/mp1.

ATTORNEY through a coil.

' Mechanical refrigerators designed for housepartment unpalatable.

' munication so that low temperature coil employed for freezing ice cubes. In this way, moisture contained in the been able to maintain better than v within the refrigeratingchamber. Furthermore, I by avoiding condensation of moisture on'the coil partment as low Patented Dee. 29. 1942 IrvingM Ketcham, oieniieadmr.

Application December 29, 1934', Serial No. 759,605 16 Claims. (cL'ez-ue) My invention relates to refrigerators, air coolers and the like and particularly to mechanical refrigerators-wherein a hold use. are ordinarily provided'with a. coil for the circulation of. a refrigerant and withtrays for the freezing of ice cubes, frozen desserts,

"refrigerant is circulated cycle, and controlling the fall below freezing (32 1''.) during the on mechanism so that the off" cycle is long enough to insure melting or evaporation of all moisture which mayjfreeze on the coils during the on cycle. Inthis way, ac-

-- cumulation of ice or frost onthe coil or other.

etc-., which are located directly adjacent the coil.

The coil also serves to cool a refrigerating comin which food is stored and for this purpose is located in contact with the air within the compartment. In order that the ice cubes may freeze quickly, the freezing coil is frequently maintained at a very low temperature, that is,

in the neighborhood of 0 F. or lower. However,' at this low temperature moisture contained in the air within the refrigerating compartment and coming incontact with the coil is condensed very rapidly, forming frost on the coils. The humidity of the refrigerating compartment is therefore'/ maintained at a very low point and food stored therein soon dries out becoming withered .and' Furthermore, the accumulation ofv frost on the coil renders it necessary to defrost the coili frequently. .In accordance tions to constructions of the prior art are overcome by providing a freezing compartment and a L refrigerating chamber which are not-in comair within the refrigerating with my invention these objeccompartment does not come in contact with thethe atmosphere in the refrigerating chamber is not withdrawn by condensation on the COflS-' I may also supply additional moisture to the air'in the refrigerating compartment and in practice have humidi y used forproducing-ice, there is much less formation of frost and defrosting of the coiidoes not have to be carried outso frequently. 4 v

' Itis no't'necessary or even desirable to main tain the temperature of the refrigerating coming chamber at average temperatures which are in the neighborhood of or somewhat by allowing the temperature of such as the coil or that portionthereof in contact with air within the above 32. F. Thisaverage temperature maybe produced 1 those surfaces refrigerating chamber to as that of the freezing-com- -partment and therefore I prefer to maintain allr ings, I have shown surfaces in contact with air within the refrigerat- 6 which is not indirectcommimication with the refrigerating chamber 1 cessive refrigerating operations.

native embodiment of my invention;

surfaces .during successive refrigerating cycles is avoided and the humidity of the air in the chamher is maintained high. Furthermore, by permitting the. coil. in the refrigerating chamber to be cooled to temperatures below freezing during the on cycle the maximum cooling effect is obtained so that the motor and compressor need only be operated for shortperiods of time.

One of the objects of my invention is to provide a refrigerator wherein the humidity of air within the refrigeratingcompartment is maintained relatively high.

Another object of my invention is to avoid the necessity for "frequent defrosting of the refrigerator coil. v

A further object of my invention is to return moisture condensed during the refrigerating cycle of operati to the atmosphere in the refrigerating cham during the fol!" cycle between suc- A further object of my'invention isto main tain theaverage temperatureof all surfaces in contact with air within the refrigerating chamber at temperatures not lower featureso'f, my.

that is, freezing temperature. These and other objects and invention will appear from the following'description thereof infwhich reference is made to the accompanying figures of the drawings.

the drawings:

Fig. 1 is an elevation of a household refrigerator.

embodying my invention with the doors thereof removed.

. Fig. 2 is a plan view-in section-of'that form of m invention illustrated ,in] Fig. 1 taken :on

the line 2-2,:and

Flg; 3 is a vertical sectional view of! rtion of a mechanical refrigerator illustrating an alter- Inthat formof invention chosenffor purposes of illustration in' Figs. 1 and-'2 of thejdr'awe a household refrigerator in the form of an'in'sulated cabinet !havinga refrigerating chamber' l and'a freezing chamber and which preferably is insulated therefrom by I. The freezingchamber is provided with a separate. door "so that even when embodied in a refrigerator havfreezing chamber is not in communication with air in the refrigerating chamber. When the refri gerator has a number of doors one may be provided specially for the freezing chamber if desired.

freezing coilflso that in reality one single con-' tinuous coil is employed; A portion of the coil therefore extends through the insulating walls 8 to provide communication between the sections l2 and Hithereof. The coils l2 and It may be of any suitable form, construction, or arrangement, but as shown, the coil I6 is located adja-' cent the outer wall 8 of the freezing chamber 6 and extends'downward adjacent one side thereof and beneath the. bottom of the freezing chamber. Vertically arranged fins l8 through which coil l8 passes are located in heat transferring relation with the air in the refrigerating chamber and serve to'improve the transfer of heat from the air to coil I5.

The operation of the mechanism thus far described is as follows: When the thermostat is actuated to start the compressor the pressure in the coil is reduced until the expansion valve leading to the coil is opened. Liquid refrigerant thenpasses through the expansion valve into coil [2 in the freezing chamber .6 and boils or evaporates immediately until the temperature of *thatportion of the coiladjacent the expansion v 2,806,480 ing a single door as shown in the drawings, the

1. The lower portion of the baille serves as I a support for a pan 22 in which water is mintained at a constant level by means of an overflow or drain pipe 24. Air circulating through the refrigerating chamberand over the refrigerating coil and fins therefore passes over thewater in pan :2 so that any deficiency in moisture in the air is overcome by evaporation of water from the pan. During the "on" period of operation in which the coil is cooled to a low temperature there is a tendency for moisture to condense out and freeze on the cooling coils and fins because the temperature of the valve is reduced to the boiling temperature of the refrigerant. The liquid refrigerant then begins to accumulate in the freezing coil and the surface of the liquid or the point at which the most vigorous boiling or evaporation of the refrigerant takes place advances along the freezing coil as the temperature thereof is lowered. When the entire coil in the freezing chamber has fallen to the boiling point of the refrigerant and the liquid refrigerant fills the same it passes over into the coil IS in the refrigerating chamber and there evaporates.

The cold vapors of the refrigerant the freezing coil 12 to the refrigerating coil it prior to" the passage of liquid into coil l6 have a relatively low refrigerating value so that rapid. cooling of the refrigerating chamber does not take place until the freezing coil is filled with vliquid refrigerant andthe freezing chamber I refrigerant until the thermostat-26 is actuated and operation of the compressor isstopped.

In order to insure effective circulation of air within the refrigerating chamber and over the coil [6 and fins I8, I provide a baiile 20 which is spaced from the top of the refrigerating chamberv and extends downwardly beside the refrigerating coil l6 and fins I8 and beneath the same at the bottom of the freezing chamber. With this construction, air is circulated directly in contact with the refrigerating coil and fins, pass y ing in at the top and out at the bottom of the baffle in the path indicated by the arrows in Fig.

passing from chamber is rapidly cooled by evaporation of the I coil and fins is below freezing. The water in pan 22 is of relatively large volume and therefore does not freeze readily so that air passing over the water becomes substantially saturated with water vapor.

The refrigerator is provided with a temperature responsive device 2' which preferably is located within the refrigerating chamber 4 and is connected to the motor 28, condenser 30, compressor 32, or to any other suitable device in the system to prevent continued operation of the mechanical elements of the refrigerator when the desired low temperature has been'attained within the refrigerating chamber. The circulation of the refrigerant from-the condenser 30 through the usual expansion valve II and through coils l2 and I8 is therefore stopped for a sufficient length of time to allow the temperature of the coils l6 and fins I8 to rise "until above freezing and melt all of the frozen moisture during the off" period of operation, Thereafter, the temperature responsive device is again actuated to repeat the operation. Thus by the use of a single unobstructed coll, part of which is located in the freezing. chamber and part in the refrigerating chamber, the temperature of each of the chambers can be maintained within. predetermined limits by means of a single thermostat in the refrigerating chamber. j

In order to prevent the accumulation of frost onthe coil l8, theadjustment of the temperature responsive device is such that after the completion of a refrigerating period, the device will not again be operated until the temperature of the air within the refrigerating chamber has risen sufiiciently to cause frost or ice formed on the coil I. and fins II to melt or evaporate, and this condition maintained until substantially all of the frost has disappeared. In this wayrthe accumulation of frost during successive refrigerating cycles is avoided and the average or mean temperature of all surfaces in contact with air in the refrigerator chamber is maintained above 32 I". I

This adjustment insures return to the ,air within the refrigerator chamber of the moisture which was condensed out or frozen on the coils during the refrigerating cycle. The moisture which is frozen on the fins and coils on melting drips downwardly over an extended surmosphere and further serves to maintain a continuous supply of water or moisture for insuring adequate humidity within the refrigerator.

While the construction described insures adequate humidity of air in the refrigerator chamber, preventing drying out of food being stored, it also reduces the amount of frost collecting on the coil I: in the freezing chamber since there is much less circulation of the air in the freez- Furthermore, the volume of air within the freezing chamber is less 'so thatless moisture is brought into contact with the coil. For this reaing chamber than in the refrigerating chamber.

son my construction also reduces the necessity I claim-:- v 1. A mechanical refrigerator comprising a freezing, chamber, a refrigerating chamber, a coilcarrying a refrigerant having one portion thereof located in-the freezing portion thereof located the upper portion of a part thereof located in a baffle spacedfrom the refrigerating chamber, the top and bottom of ber and defining a narrow path for the fiow of freezing chamber and heat through the chamber wall, aided preferably by fins or the like on the external surface of the freezing chamberfor cooling the air within the refrigerated chamber. This construction is illustrated by the construction shown in Fig. 3 where'- in a casing 34 encloses the freezing coil I! which may be the only coll employed. The outer surface of casing 34 is preferably provided with fins 36 formed integral therewith and extending between the outer surface of the casing and a baffle 38 which may be supported by the casing 34. A pan 40 may also be supported 'bythe casing 34 to collect and retain moisture as in the construction of Figs. 1 and 2.

Cooling of the refrigerator compartment in the arrangement of Fig. 3 is effected by circulation of air downwardly overthe fins 36 between the casing 34 and baflie casing. The casing and fins are cooled by con- 38 and incontact with the duction between the cold'freezing compartment and the fins and casing. If desired, suitable insulation 42 may be provided to prevent cooling of the fins and casing to such an extent that frost will accumulate and build up on the casing during successive refrigerating periods. The function of the pan of water in preserving the desired high humidity in the chamber issimilar to that in the construction of Figs. 1 and 2 so that food stored in the refrigerating chamber is kept fresh for long-periods of time.

In some constructions it may be preferable'to form the casing 34 integral with the inner liningof the refrigerating chamber and freezing charnber. However, the construction of Fig. 3 also lends itself to use as an attachment to be applied to existing constructions in which the coil is exposed to the air in the refrigerating chamber. For this reason, I have shown the casing 34 as provided with brackets for attachmentto the walls of the cabinet by means of bolts or the like; The casing may be formed with a door and may abut against the net 2 or otherwise vent access of air from the refrigerating chamber 6 to the coil. In this way, the device may be .obtain the" applied to existing constructions to advantages of my invention without the'necessity of purchasing a new refrigerator.

Those forms of my described are typical of various embodiments thereof which may be employed. However, nil- "merous changes and modifications may be made inner surface of the cabi,-' to enclose the coil l2 and pre-' said chamberanddefining tending substantially the coil by convection, taining the air by convection between the 'baflie and the overthat portion of the coil in the refrigeratingchamber, and means serving to maintain the average temperature of that portion of the coil in the refrigeratingchamrber in the neighborhood of 32 F.

2. A mechanical refrigerator having means forming a freezing chamber located in the upper portion of the refrigerator, and means forming .a'refrigerating chamberinsulated from the freezing chamber, a coil carrying refrigerant having a portion thereof located the latter portion of said coil neath the freezing vertically between said portion of the coil and the refrigerating chamber and spaced from the top ,and bottomthereof to define a narrow path for the flow of air over and a control device mainaverage-temperature of that portion of the coil in the refrigerating chamber in the neighborhood of 32 F.

-3."A mechanical refrigerator comprising a freezing chamber, a refrigerating chambena coil carrying a refrigerant having dne portion thereof located in the refrigerating chamber; the latter portion of said cell lying adjacent said freezing chamber at the side thereof and having at least a portion thereof located in the" uppe: portion the refrigerating chamin the freezing cham ber and another portion located in the refri crating chamber, extending downwardly along one side of and bechamber, and a bame exchamber and another t in the refrigerating chambensaid other portion being positioned ad: I jacent thefreezing chamber and having at least of. the refrigerating chamber, a substantiallv ver- 7 tical baffle spaced from the top and bottom of the .fiow of air by convection over that portion invention herein shown and in the form and arrangementsjof the parts and therefore it should be understood that ;I do not intend my invention to belimited to the illustrative embodiments thereof 'set forth except as defined byv the claims.

narrow path for the ingcompartment and a refrigerating of the coil in the refrigerating chamber and means located adjacent the lower portion of the baflle for supplying moisture to air passing downwardly over the coil.

4. A mechanical refrigerator having means forming a freezing chamber located in the upper portion of the refrigerator, andv means forming a refrigerating chamber insulated from the freezing chamber, a coil carrying refrigerant having,

a portion thereof located in thefreezing chama narrow path for her and another portion located in the refrigerating chamber, the latter portion of said coil extending downw'ardlyalon'g one side of and be-' 'neath' thegfreezing chamber, a baffle extending substantially vertically "between said portion of the coil 'and the refrigerating chamber and spaced fromthe top and bottom thereof to define a I flow. of air overthe coil by convection, a drip pan portion of the coil in the refrigerating chamber to-receive water falling from thecoilrand serving to deflect downwardly flowing air so that itlpasses over the surface of water therein, and a control device maintaining the 5 average temperatur of that portion of the coil in the refrigerating chamber in the neighborhood of 32 F. a v

5. In a mechanical refrigerator havin storage located beneath that I a freez- Y compartment, the combination of a freezing coil in said freezing compartment, means for insulating said freezing compartment from said refrigerating storage compartment, a refrigerating coil in said refrigerating compartment, said'refrigerating coil extending about said freezing compartment on at least two sides thereof, and

a complementary baffle plate in said refrigerating I storage compartment spaced from and parallel to said refrigerating coil to direct air along the sides of said refrigerating coil. I

6. The combination according to claim 5 in which said baille plate includes means for retaining moisture, so positioned that the air directed along the sides of said refrigerating coil passes over said moisture retaining means so that the humidity of the air in said refrigerating compartment will be increased.

7. In a refrigerating unit, the combination of an L-shaped heat-exchanging device including a conduit, part .of which is distributed within one plane and the other part of which is distributed within a plane at right angles to the one plane, and an L-shaped complementarybaffreezing compartment from said refrigerating compartment, a refrigerating coil in said refrigerating compartment, moisture retaining means positioned beneath said refrigerating coil for catching and. retaining the condensate formed on said coil, means for automatically draining off excess moisture caught in said moisture retaining means, and'a baflle for directing warm air in said refrigerating compartment over saidrefrigerating coil between said bailie and freezing compartment.

9. A freezing and refrigerating unit for refrigsaid ' erators, comprising means forming an insulated freezing compartment, a freezing coil therein, a refrigerating coil serially connected to said freezing coil and positioned relatively closely to said freezing compartment, and a complementary bafmeans .for introducing refrigerant'to the top of said conduit whereby there will be a gravity flow of such refrigerant resulting in rapid distribution thereof to assist thinly spreading any frost on said conduit over a large area, and a return conduit connected to the bottom of said first conduit and passing upward and over said first conduit, whereby the'entering warm air will act on said return conduit and assure complet evaporation of any residual refrigerant.

12. In a refrigerator having a freezing compartment and a refrigerating compartment, in

resulting in rapid distribution thereof to assist fie mounted adjacent said freezing compartment means and spaced outside of said refrigerating coil, said baiile including moisture collecting 'and retaining means.

10. In a refrigerator, in combination, a heat thinly spreading any frost on said conduit over a large area, and a return conduit connected to the bottom of said first conduit and passing upward over said first conduit, whereby the entering warm air will act on said return conduit and insure complete evaporation of any residual refrigerant.

13. In a refrigerator having a freezing compartment and a, refrigerating compartment in combination, a freezing coil in said freezing compartmenty-a refrigerating coil in said refrigerating compartment including a conduit at least a part of which is distributed within a generally vertical plane, means for directing the warm air in said refrigerating compartment downward along said conduit, humidifying means attached to said air directing means, means for introducing refrigerant to the top of said conduit whereby there will .be a gravity flow of such refrigerant resulting in rapid distribution thereof to assist thinly spreading any frost on said conduit over a large area, and a return 'conduit connected to the bottom of said first conduit and passing upward over' said first conduit, whereby the entering warm air will react on said return conduit and insure complete evaporation of an residual refrigerant.

14. A mechanical refrigerator having a freez ing chamber and a refrigerating chamber insuexcha'nging device including a conduit at least a part of which is distributed within a generally vertical plane, a cooperating battl for directing the warm air in said refrigerator downward along said. conduit, means for introducing refrigerant lated therefrom, a coil having a portion thereof located in said freezing chamber and surrounding the contents of said freezing chamber in close heat-exchange relationship, means for supplying a refrigerant to said coil portion at such a pressure that said refrigerant will boil until I the temperature of said freezing chamber apto the 'top of said conduit whereby there will be a'gravity flow of such refrigerant resulting in rapid distribution thereof to assist thinly spreading-any frost on said conduit over a large area, and a return conduit connected to the bottomof said first conduit and passing upward over said first conduit, whereby the entering exchanging device including a conduit at least proximates that of said refrigerant, a second coil said second coil portion being positioned in a a part of which is distributed within a generally vertical plane, means for directing the warm air in said refrigerator downward along said conduit,

substantially vertical plane and connected at its top to said first coil portion, whereby ther will be a rapid gravity flow of the refrigerant in said second coil portion, temperature responsive means for controlling the flow of' refrigeration through said second coil portions to maintain its temperature in the neighborhood of 32 F., whereby due; to the rapid gravity flow of refrigeration in said second coil portion accumulation of frost on said second coil portion is retarded, and means for humidifying the air in said refrigerating chamber.

taining the condensate formed on said coil, means for automatically draining off excess moisture caught in said moisture retaining means, and a baiile positioned adjacent said'freezing compartment, said refrigerating coil beingpositioned between said baffle and the wall of said freezing means positioned, bec means maintaining the compartment, whereby said baflle .directs the air in said refrigerating compartment over aid refrigerating coil between said bat le and the warm freezing compartment. I 16. A mechanical refrigerator having in combination a freezing chamber, a refrigerating chamber insulated from said freezing chamber,-

coils carrying refrigerant located in said freezing and refrigerating chambers, moistur supplying means to air in said refrigerating chamber,- and average temperature of the coil in the" refrigerating chamber above that of the coil in the freezing'chamber and in the neighborhoodof 32 F. A

' f IRVINGM. KETCHAM. 

